package com.atlassian.vcache.internal.core.service;
   
   import com.atlassian.utt.concurrency.Barrier;
   import com.atlassian.vcache.VCacheException;
   import com.google.common.base.Throwables;
   import org.junit.Test;
   
   import java.time.Duration;
   import java.util.concurrent.CompletableFuture;
  
  import static com.atlassian.vcache.internal.test.CompletionStageSuccessful.successfulWith;
  import static com.atlassian.vcache.internal.test.TestUtils.runAndWaitForStart;
  import static org.hamcrest.Matchers.instanceOf;
  import static org.hamcrest.Matchers.is;
  import static org.junit.Assert.assertThat;
  import static org.junit.Assert.fail;
  
  public class VCacheLockTest {
  
      @Test
      public void timeout() {
          // T1: get the lock and await signal
          // T2: attempt to get the lock
          // Confirm T2 times out
  
          final Barrier blockedInSupplier = new Barrier();
          final Barrier resumeInSupplier = new Barrier();
          final VCacheLock lock = new VCacheLock("noname", Duration.ofMillis(100));
  
          final CompletableFuture<String> t1Result =
                  runAndWaitForStart(() -> lock.withLock(() -> {
                      blockedInSupplier.signal();
                      resumeInSupplier.await();
                      return "T1";
                  }));
  
          blockedInSupplier.await();
          final CompletableFuture<String> t2Result =
                  runAndWaitForStart(() -> lock.withLock(() -> "T2"));
  
          // Wait for the result from T2 to ensure it has run to completion.
          try {
              t2Result.join();
              fail("Expected to get an error");
          } catch (Exception e) {
              final Throwable reasonEx = Throwables.getRootCause(e);
              assertThat(reasonEx, instanceOf(VCacheException.class));
              assertThat(reasonEx.getMessage(), is("Timed out waiting for lock on cache: noname"));
          }
  
          resumeInSupplier.signal(); //Wait until T2 completed before resuming.
  
          assertThat(t1Result, successfulWith(is("T1")));
      }
  }